Prevent DialogFragment from dismissing when button is clicked

Question

I have a DialogFragment with a custom view which contains two text fields where the user is to input their username and password. When the positive button is clicked, I want to validate that the user actually did input something before dismissing the dialog.

public class AuthenticationDialog extends DialogFragment {      public Dialog onCreateDialog(Bundle savedInstanceState) {         AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());         LayoutInflater inflater = getActivity().getLayoutInflater();         builder.setView(inflater.inflate(R.layout.authentication_dialog, null))             .setPositiveButton(getResources().getString(R.string.login), new DialogInterface.OnClickListener() {                 public void onClick(DialogInterface dialog, int which) {                     // TODO                 }             })             .setNegativeButton(getResources().getString(R.string.reset), new DialogInterface.OnClickListener() {                 public void onClick(DialogInterface dialog, int which) {                     // TODO                 }             });          return builder.create();     } } 

So how can I prevent the dialog from dismissing? Is there some method I should override?

Answer 1

Override the default button handlers in OnStart() to do this.

@Override public Dialog onCreateDialog(Bundle savedInstanceState) {     AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());     builder.setMessage("Test for preventing dialog close");     builder.setPositiveButton("Test",          new DialogInterface.OnClickListener()         {             @Override             public void onClick(DialogInterface dialog, int which)             {                 //Do nothing here because we override this button later to change the close behaviour.                  //However, we still need this because on older versions of Android unless we                  //pass a handler the button doesn't get instantiated             }         });     return builder.create(); }  @Override public void onStart() {     super.onStart();    //super.onStart() is where dialog.show() is actually called on the underlying dialog, so we have to do it after this point     AlertDialog d = (AlertDialog)getDialog();     if(d != null)     {         Button positiveButton = (Button) d.getButton(Dialog.BUTTON_POSITIVE);         positiveButton.setOnClickListener(new View.OnClickListener()                 {                     @Override                     public void onClick(View v)                     {                         Boolean wantToCloseDialog = false;                         //Do stuff, possibly set wantToCloseDialog to true then...                         if(wantToCloseDialog)                             dismiss();                         //else dialog stays open. Make sure you have an obvious way to close the dialog especially if you set cancellable to false.                     }                 });     } } 

See my answer here https://stackoverflow.com/a/15619098/579234 for more explanation and examples on other dialog types too.